This invention is drawn to an apparatus for sensing changes in flow of a fluid, and more specifically, an apparatus for sensing changes in flow of fuel through a pressurized automotive fuel system.
Current automotive or vehicular fuel systems provide pressurized fuel from the fuel tank to the vehicle's engine. Generally, these fuel systems include a fuel pressure regulator to control the pressure of the fuel through the fuel system. To enable the pressure regulator to maintain good fuel regulation, and to keep the fuel operating temperature at a minimum, a substantial amount of excess fuel is supplied to the engine from the fuel tank than is actually used by the engine. The fuel which is not used by the engine is subsequently returned back to the fuel tank.
Since the automotive fuel system includes a fuel line from the fuel tank to the engine, and a fuel line from the engine back to the fuel tank, as well as a variety of fuel system components along the way, there are a number of places where fuel system integrity could be breached and cause fuel leakage, especially since the fuel system is pressurized. Further, catastrophic loss of fuel system integrity as a result of collisions or the like provides additional concerns. For many obvious reasons, leakage of fuel from the fuel system could cause a number of serious problems. Current automotive fuel systems incorporate clips, latches, or check valves at the connections between the fuel lines and the different components to prevent fuel leakage by increasing the durability of the fuel system. Although these devices provide additional integrity against the leakage of fuel from the fuel system, they add a certain amount of excessive cost to the fuel system, and further, cannot provide an indication of leakage within the fuel system if it happens to occur. Moreover, these devices do not provide safety mechanisms in the event of catastrophic fuel system leakage, such as may occur from an automobile accident or the like. In addition, current automotive fuel systems do not provide adequate means for determining certain malfunctions of the fuel system components.
What is needed then is an automotive fuel system incorporating means for providing an indication of loss of fuel system integrity from either fuel leakage within the fuel system or other fuel system component malfunction, and to stop the fuel pump in the event of catastrophic loss of fuel system integrity. It is therefore an object of this invention to provide such a means.